When a display apparatus is switched to its off-state, a display screen of a display device of the display apparatus has an appearance which is not in harmony with its surrounding. Usually, the display screen is rather black when no image is displayed.
WO 02/084695 discloses a picture display device, which has an active part (the display screen) on which pictures are displayed. An LC shutter of a size corresponding to the size of the active part of the display device is fixed to the surface of the display device in front of the display device. The LC shutter is energized in accordance with the on/off operation of the display device. The LC shutter comprises an LC cell with an LC gel, which can be switched between a light-transmissive state and an opaque, particularly scattering, state. The LC shutter is transparent when the display device is in the on-state and is opaque in the off-state. In the opaque state of the LC shutter, the display screen is hidden for an observer and thus is less disturbing in its surroundings.
However, a problem with the LC shutter is that its hiding effect is limited. If the LC shutter provides a good hiding effect, the shutter appears to be either a little diffuse in its transmissive state during the on-state of the display apparatus, or another layer needs to be provided which simultaneously increases the ambient light reflection but reduces the daylight contrast.